Dinner timing irregularity was independently associated with higher depressive symptom scores (B = 1.08, 95% CI 0.32–1.85, P = 0.006) in Iranian adults, while breakfast and lunch irregularities showed no significant associations with depression, anxiety, or stress.
Key Findings
Results
Dinner timing irregularity was independently associated with higher depressive symptom scores in linear regression models.
The regression coefficient was B = 1.08 (95% CI 0.32–1.85, P = 0.006).
This association was independent of covariates including sleep quality, chronotype, physical activity, anthropometrics, and sociodemographics.
The analysis included 404 participants with complete data for all model variables.
The association held in continuous linear regression models but not in multivariable logistic regression for binary outcomes.
Results
Dinner timing irregularity was not significantly associated with stress or anxiety scores.
The P-value for the association between dinner irregularity and stress was P = 0.336.
The P-value for the association between dinner irregularity and anxiety was P = 0.388.
Mental health outcomes were measured using the Depression Anxiety Stress Scales short form (DASS).
Results
Breakfast and lunch timing irregularities showed no significant associations with depression, anxiety, or stress.
Neither breakfast nor lunch composite phase deviation (CPD) scores were significantly associated with any of the three mental health outcomes.
Meal timing irregularity was assessed using composite phase deviation (CPD) scores derived from three non-consecutive 24-hour dietary recalls.
CPD scores captured day-to-day variability and deviation from participants' habitual meal timing for each meal separately.
Results
No significant associations were found between meal timing irregularity tertiles and binary mental health outcomes.
All adjusted P-trend values were greater than 0.05 for binary mental health outcomes across all three meal types.
Binary outcomes were analyzed using multivariable logistic regression.
This contrasts with the significant association found when depressive symptoms were treated as a continuous variable.
Methods
The study sample consisted of 450 apparently healthy Iranian adults recruited via convenience sampling.
Participants were aged 20–59 years, with 53.8% female.
Dietary data were collected using three non-consecutive 24-hour recalls.
Covariates assessed included sleep quality (Pittsburgh Sleep Quality Index), chronotype (Morningness-Eveningness Questionnaire), and physical activity (International Physical Activity Questionnaire).
The study design was cross-sectional, precluding causal inference about the direction of the observed association.
What This Means
This research suggests that the timing of the evening meal — specifically how much it varies from day to day — may be linked to higher levels of depressive symptoms in adults. The study followed 450 Iranian adults and measured how irregular their breakfast, lunch, and dinner times were across three different days. Only dinner timing irregularity was linked to more depressive symptoms, and this finding held even after accounting for factors like sleep quality, physical activity, body size, and chronotype (whether someone is naturally a morning or evening person). Morning and midday meal timing did not show similar associations.
Interestingly, this association only appeared when depression was measured as a numerical score along a spectrum, not when participants were simply classified as 'depressed' or 'not depressed.' The researchers also found no meaningful links between any meal timing irregularity and anxiety or stress scores. This suggests that irregular dinner timing may have a specific and relatively subtle relationship with mood rather than with broader mental health difficulties.
Because this was a cross-sectional study — meaning it captured a single snapshot in time — it cannot determine whether irregular dinner timing causes depressive symptoms, whether depressive symptoms lead people to eat at irregular times, or whether both are driven by some other underlying factor. The authors call for future studies that follow people over time or test interventions to better understand this relationship and the biological mechanisms that might explain it.
Check Your Own Numbers
Upload your bloodwork. We'll cross-reference your results against this study and 4,700 others.
Dankoob V, Ostevari A, Jabbarzadeh-Ganjeh B, Mirrafiei A, Norouziasl R, Ghaemi S, et al.. (2026). Evening meal timing irregularity is associated with higher depressive symptoms in Iranian adults: A cross-sectional study.. Journal of affective disorders. https://doi.org/10.1016/j.jad.2026.122404